Power storage device exchange system

Abstract

To provide a power storage device exchange system capable of suppressing overcurrent when connected in parallel for a vehicle equipped with a switching circuit capable of switching between series connection and parallel connection of a plurality of power storage devices.SOLUTION: A power storage device exchange system includes a charging device and an exchange device. The exchange device is configured to exchange a power storage device of a target vehicle. The target vehicle includes a plurality of power storage devices and a first switching circuit. The first switching circuit is configured to be able to switch between a series state in which the plurality of power storage devices are connected in series and a parallel state in which the plurality of power storage devices are connected in parallel. In the power storage device exchange system, when the exchange device exchanges a first power storage device and a second power storage device mounted on the target vehicle with a third power storage device and a fourth power storage device, prior to the exchange, the charging device charges at least one of the third power storage device and the fourth power storage device so as to reduce a voltage difference between the third power storage device and the fourth power storage device.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a power storage device exchange system. [Background technology]

[0002] Japanese Patent No. 6371450 (Patent Document 1) discloses that the overall performance of an electric vehicle powered by multiple batteries depends on the performance of the battery with the least remaining battery charge. Patent Document 1 also discloses that it is preferable that the remaining battery charges of multiple batteries stored at a battery station be equal when the electric vehicle arrives. In the power storage device exchange system described in Patent Document 1, the supply amount of power to be supplied from one or more batteries loaded in a charger of the battery station to other batteries is determined so that the remaining battery charges (Ah) of the multiple batteries approach an equal value by the time the electric vehicle arrives at the battery station. A management server transmits information regarding the supply amount to the battery station. The battery station controls the charging of the batteries loaded in the charger based on the information received from the management server. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6371450 Summary of the Invention [Problem to be solved by the invention]

[0004] In the vehicle described in Patent Document 1, the performance of the entire vehicle depends on the performance of the power storage device with the least remaining battery charge. For this reason, it is considered that multiple batteries (power storage devices) are connected in series in the vehicle. On the other hand, it is considered that a switching circuit is provided in a vehicle equipped with multiple power storage devices so that the voltage of the vehicle's power storage unit can be changed depending on the situation, for example. The switching circuit is configured to be able to switch between a series state in which the multiple power storage devices are connected in series and a parallel state in which the multiple power storage devices are connected in parallel.

[0005] The power storage device exchange system described in Patent Document 1 provides a vehicle with multiple batteries with the same remaining battery capacity (Ah). The relationship (voltage characteristics) between the battery voltage (V) and the amount of stored power (Ah) varies from battery to battery. When multiple power storage devices with the same amount of stored power are connected in parallel, there is a possibility that a momentary overcurrent will occur due to the voltage difference between the power storage devices. When the system described in Patent Document 1 is applied to a vehicle equipped with the above-mentioned switching circuit, the switching circuit will be prone to deterioration due to the overcurrent that occurs when the devices are connected in parallel.

[0006] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a storage device exchange system that can suppress overcurrent when multiple storage devices are connected in parallel for a vehicle equipped with a switching circuit that can switch between series connection and parallel connection. [Means for solving the problem]

[0007] According to one embodiment of the present disclosure, there is provided an exchange system for a power storage device as described below.

[0008] The power storage device exchange system is a system for exchanging power storage devices and includes a charging device and an exchange device. The exchange device is configured to exchange the power storage device of a target vehicle. The target vehicle includes a plurality of power storage devices and a first switching circuit. The first switching circuit is configured to be able to switch between a series state in which the plurality of power storage devices are connected in series and a parallel state in which the plurality of power storage devices are connected in parallel. In the power storage device exchange system, when the exchange device exchanges the first and second power storage devices mounted on the target vehicle with a third and fourth power storage device, prior to the exchange, the charging device charges at least one of the third and fourth power storage devices so as to reduce a voltage difference between the third and fourth power storage devices.

[0009] According to the above configuration, before the third power storage device and the fourth power storage device are attached to the target vehicle, at least one of the third power storage device and the fourth power storage device is charged so that the voltage difference between the third power storage device and the fourth power storage device is small, thereby suppressing overcurrent when the third power storage device and the fourth power storage device attached to the target vehicle are connected in parallel. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide an energy storage device exchange system that can suppress overcurrent when multiple energy storage devices are connected in parallel for a vehicle equipped with a switching circuit that can switch between series connection and parallel connection. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating a configuration (first switching circuit) of a vehicle according to an embodiment of the present disclosure. [Figure 2] 2 is a diagram showing the circuit configurations of a vehicle body and a battery pack according to the present embodiment; FIG. [Figure 3] 1 is a diagram illustrating an example of the configuration of a battery exchange system according to an embodiment of the present invention. [Figure 4] FIG. 10 is a diagram for explaining an exchange request according to the present embodiment. [Figure 5]3 is a flowchart showing a battery replacement method according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals and their description will not be repeated.

[0013] FIG. 1 is a diagram showing the configuration of a vehicle according to this embodiment. Referring to FIG. 1, vehicle 100 includes a vehicle body 10 and battery packs 20A and 20B. Vehicle body 10 is the portion of vehicle 100 other than battery packs 20A and 20B. Vehicle 100 is configured to be able to run using electric power stored in battery packs 20A and 20B. Vehicle 100 is, for example, an electric vehicle (BEV) without an internal combustion engine. However, the vehicle is not limited to this, and may also be a PHEV (plug-in hybrid vehicle) with an internal combustion engine, or another electrically powered vehicle (xEV).

[0014] The vehicle body 10 is equipped with a switching circuit 30. The switching circuit 30 is configured to be able to switch between a series state in which the battery packs 20A, 20B are connected in series and a parallel state in which the battery packs 20A, 20B are connected in parallel. The switching circuit 30 includes three relays R1, R2, and R3. The relay R1 is provided on an electric wire EL1 connecting the positive terminal of the battery pack 20A to the positive terminal of the battery pack 20B. The relay R2 is provided on an electric wire EL2 connecting the positive terminal of the battery pack 20A to the negative terminal of the battery pack 20B. The relay R3 is provided on an electric wire EL3 connecting the negative terminal of the battery pack 20A to the negative terminal of the battery pack 20B. The electric wires EL1 and EL2 are connected to each other at a node N1. The electric wires EL2 and EL3 are connected to each other at a node N2. The voltage of the mutually connected battery packs 20A and 20B is output between terminal T1 (positive terminal) and terminal T2 (negative terminal) via the switching circuit 30. Terminals T1 and T2 are provided on electric wires EL1 and EL3, respectively. Relay R1 is located between terminal T1 and node N1. Relay R3 is located between terminal T2 and node N2. When relays R1, R2, and R3 are OFF, ON, and OFF, respectively, the battery packs 20A and 20B are connected in series (series state). When relays R1, R2, and R3 are ON, OFF, and ON, respectively, the battery packs 20A and 20B are connected in parallel (parallel state). Electromagnetic mechanical relays can be used as the switching relays (relays R1, R2, and R3) that switch between the series state and the parallel state. However, instead of this, semiconductor relays may be used. The switching circuit 30 may switch between a series drive system (for example, an 800V drive system) and a parallel drive system (for example, a 400V drive system) that operates at a lower voltage than the series drive system. Hereinafter, the series and parallel states of battery packs 20A and 20B in vehicle 100 may be referred to as vehicle 100 being in a series or parallel state, respectively.

[0015] The vehicle body 10 further includes an HMI (Human Machine Interface) 19a and a communication device 19b. The HMI 19a includes an input device and a display device. The HMI 19a may include a touch panel display. The communication device 19b is configured to be capable of wireless communication with the mobile terminal 600 and a server 380 (FIG. 3) described later.

[0016] FIG. 2 is a diagram showing the circuit configurations of the vehicle body 10 and each of the battery packs 20A and 20B. Referring to FIG. 2, the vehicle body 10 includes an SMR 13 and an ECU 500. The battery pack 20A includes a battery 21a, a BMS 22a, an SMR 23a, an ECU 28a, electric wires PL2a and PL3a, a communication line CL2a, and terminals T21a and T22a. The battery pack 20B includes a battery 21b, a BMS 22b, an SMR 23b, an ECU 28b, electric wires PL2b and PL3b, a communication line CL2b, and terminals T21b and T22b. "ECU" stands for Electronic Control Unit. "BMS" stands for Battery Management System. "SMR" stands for System Main Relay.

[0017] In vehicle 100, the ECUs are connected to each other so that they can communicate with each other via an in-vehicle network such as a CAN (Controller Area Network). Each ECU includes a processor and a storage device. The storage device is configured to be able to save stored information. The storage device stores various information in addition to programs. In this embodiment, various controls are performed by the processor executing the programs stored in the storage device.

[0018] In this embodiment, battery packs 20A and 20B have the same configuration, and therefore, when there is no need to distinguish between them, they will be referred to as "battery pack 20." Similarly, each of batteries 21a and 21b will be referred to as "battery 21," each of BMSs 22a and 22b as "BMS 22," each of SMRs 23a and 23b as "SMR 23," each of ECUs 28a and 28b as "ECU 28," each of electric wires PL2a and PL2b as "electric wire PL2," each of electric wires PL3a and PL3b as "electric wire PL3," each of communication lines CL2a and CL2b as "communication line CL2," each of terminals T21a and T21b as "terminal T21," and each of terminals T22a and T22b as "terminal T22."

[0019] In the battery pack 20, the electric wires PL2 and PL3 function as a high-voltage power supply line and a low-voltage power supply line, respectively. The battery 21 applies a voltage to the electric wire PL2. The electric wire PL2 is connected to a terminal T21 via the SMR 23. The SMR 23 switches between connection and disconnection between the battery 21 and the terminal T21. The electric wire PL3 (low-voltage power supply line) and the communication line CL2 (dashed line in FIG. 2) are each connected to a terminal T22. The electric wire PL3 and the communication line CL2 are each connected to an ECU 28.

[0020] The ECU 28 corresponds to a control device (Bat-ECU) that monitors the state of the battery 21 and controls the SMR 23. The battery 21 is a secondary battery such as a lithium-ion battery, a nickel-metal hydride battery, or a sodium-ion battery. The secondary battery may be a liquid secondary battery or an all-solid-state secondary battery. A plurality of secondary batteries may form a battery pack. The BMS 22 detects the state (current, voltage, temperature, etc.) of the battery 21 and outputs the detection result to the ECU 28. The BMS 22 also has a SOC (State of Charge) measurement function and outputs a measured value of the SOC of the battery 21 to the ECU 28. The SOC is, for example, the ratio of the current amount of charge to the amount of charge in a fully charged state, expressed as 0 to 100%. Known methods such as a current integration method or an OCV (open circuit voltage) estimation method can be used to measure the SOC. Note that at least a portion of the functions of the BMS 22 may be implemented in the ECU 28. For example, the BMS 22 may be a battery monitoring unit. The battery monitoring unit may transmit the detected values ​​(input values ​​from each sensor) of the temperature, current, and voltage of the battery 21 to the ECU 28, and the ECU 28 may determine the SOC and SOH (State of Health) of the battery 21 from the voltage and current of the battery 21.

[0021] The ECU 28a of the battery pack 20A receives the measured value of the SOC of the battery 21a from the BMS 22a (hereinafter referred to as "SOC A The ECU 28b of the battery pack 20B transmits the measured value of the SOC of the battery 21b (hereinafter referred to as "SOC") acquired from the BMS 22b to the ECU 500 as information indicating the SOC of the battery pack 20A. B ") to the ECU 500 as information indicating the SOC of the battery pack 20B. The ECU 500 receives information indicating the battery state (SOC A ,SOC B (including

[0022] The vehicle body 10 is equipped with a vehicle drive device. The vehicle drive device includes an MG (Motor Generator) 11a and an inverter 11b. The MG 11a functions as a traction motor. The inverter 11b functions as a drive circuit for the MG 11a. The inverter 11b drives the MG 11a using power output between terminals T1 and T2 from the battery packs 20A and 20B. The MG 11a converts the power into torque to rotate the drive wheels of the vehicle 100. The MG 11a performs regenerative power generation, for example, when the vehicle 100 decelerates, and charges the battery packs 20A and 20B.

[0023] Vehicle body 10 is equipped with a charging system for external charging (charging using power supplied from outside the vehicle). The charging system includes an AC charger 15a and an AC inlet 15b for AC (alternating current) charging, and a DC charging relay 14a and a DC inlet 14b for DC (direct current) charging. DC inlet 14b and AC inlet 15b are configured to be connectable to a charging cable of a DC power supply facility and an AC power supply facility, respectively. DC inlet 14b and AC inlet 15b each output a signal indicating whether a charging cable is connected to ECU 500. DC charging relay 14a is disposed in a DC charging line connecting DC inlet 14b and battery packs 20A and 20B, and switches between connecting and disconnecting the DC charging line. AC charger 15a is disposed in an AC charging line connecting AC inlet 15b and battery packs 20A and 20B, and performs power conversion (e.g., AC / DC conversion) and switches between connecting and disconnecting the AC charging line. The DC charging relay 14 a and the AC charger 15 a are controlled by the ECU 500 .

[0024] The vehicle body 10 includes electric wires PL1a and PL1b. The electric wires PL1a and PL1b function as a high-voltage power supply line and a low-voltage power supply line, respectively. The SMR 13 is located between the electric wire PL1a and terminals T1 and T2, and switches between connection and disconnection between them. The electric wire PL1a (high-voltage power supply line) is provided with an MG 11a, an inverter 11b, a DC charging relay 14a, a DC inlet 14b, an AC charger 15a, and an AC inlet 15b. The vehicle body 10 further includes an auxiliary battery 17 that supplies power to auxiliary devices mounted on the vehicle 100. The auxiliary battery 17 applies a voltage lower than the voltage of the battery 21 to the electric wire PL1b. The electric wire PL1b (low-voltage power supply line) is connected to, for example, an ECU 500, an HMI 19a, and a communication device 19b. The vehicle body 10 further includes a DC / DC converter 16 that transforms DC power between the electric wire PL1a and the electric wire PL1b. The capacity of the auxiliary battery 17 is smaller than the capacity of the battery 21. When the amount of stored electricity in the auxiliary battery 17 becomes low, the DC / DC converter 16 steps down the DC power from the electric wire PL1a and outputs it to the auxiliary battery 17.

[0025] The vehicle body 10 further includes terminals T11A and T12A to which the battery pack 20A can be attached / detached, and terminals T11B and T12B to which the battery pack 20B can be attached / detached. Each of the terminals T11A and T11B is connected to an electric wire PL1a via the SMR 13 and the switching circuit 30. Each of the terminals T12A and T12B is connected to an electric wire PL1b (low-voltage power supply line) and a communication line CL1 (dashed line in FIG. 2) inside the vehicle body 10. Each of the terminals T21a and T22a of the battery pack 20A is configured to allow the vehicle body 10 to be attached / detached. Each of the terminals T21b and T22b of the battery pack 20B is also configured to allow the vehicle body 10 to be attached / detached. Terminals T21a and T22a are connected to terminals T11A and T12A, respectively, and terminals T21b and T22b are connected to terminals T11B and T12B, respectively, whereby battery packs 20A and 20B are mounted on vehicle body 10 and vehicle 100 is completed. In vehicle 100, communication line CL1 of vehicle body 10, communication line CL2a of battery pack 20A, and communication line CL2b of battery pack 20B are connected. These communication lines form an in-vehicle network (e.g., CAN) of vehicle 100.

[0026] The battery packs 20A and 20B mounted on the vehicle 100 can be replaced with other battery packs. Fig. 3 is a diagram showing an example of the configuration of a battery exchange system for exchanging battery packs.

[0027] 3, the battery exchange system 300 is configured to remove a battery pack installed in the vehicle 100 from the vehicle body 10 and attach another battery pack to the vehicle body 10. The battery exchange system 300 shown in FIG. 3 is installed in an exchange station. In this embodiment, the location of the exchange station corresponds to an example of a "predetermined area" according to the present disclosure.

[0028] The battery exchange system 300 includes a first storage device 310, a second storage device 320, a collection device 330, a filling device 340, and an exchange device 350. The battery exchange system 300 further includes a server 380 that controls each of these devices. The server 380 includes a processor, a storage device, and a communication device. The storage device stores information about each battery pack present in the battery exchange system 300, distinguishing them by the identification information of the battery pack. In this embodiment, the server 380 corresponds to an example of a "management device" according to the present disclosure.

[0029] FIG. 3 shows an example in which battery packs 20A and 20B are simultaneously removed from vehicle 100 and two replacement battery packs are simultaneously installed in vehicle 100. Hereinafter, the two battery packs removed from vehicle 100 may be referred to as "battery packs B11 and B12." Furthermore, the two battery packs installed in vehicle 100 in place of battery packs B11 and B12 may be referred to as "battery packs B21 and B22." Each of battery packs B11, B12, B21, and B22 has the configuration of the battery pack shown in FIG. 2. Battery packs B21 and B22 installed in vehicle body 10 function as battery packs 20A and 20B (FIGS. 1 and 2) in vehicle 100. Battery packs 20A and 20B may be replaced one by one in sequence, or only one of them may be replaced.

[0030] The first storage device 310 stores a plurality of battery packs to be supplied to a vehicle. In addition to a pack storage section, the first storage device 310 includes a supply device 311 and a charging device 312. The charging device 312 includes power supplies PS1 and PS2 and a switching circuit 30A. The battery packs B21 and B22 are set in the charging device 312 before being attached to the vehicle body 10, and a BMS is provided for each battery pack. Specifically, BMSs 312a and 312b are provided to detect the states of battery packs B21 and B22, respectively. Each of the BMSs 312a and 312b includes a current sensor, a voltage sensor, and a temperature sensor, and has an SOC measurement function.

[0031] The switching circuit 30A is configured to be able to switch between a series state in which the battery packs B21 and B22 are connected in series and a parallel state in which the battery packs B21 and B22 are connected in parallel. In this embodiment, the switching circuit 30A has the same configuration as the switching circuit 30 shown in FIG. 1. Specifically, the switching circuit 30A includes relays R1A, R2A, and R3A. The relays R1A, R2A, and R3A have the same functions as the relays R1, R2, and R3, respectively. The charging device 312 can charge only one of the battery packs B21 and B22 or both simultaneously. Note that charging the battery pack B21 or B22 refers to charging the battery 21 in the battery pack B21 or B22. During charging, the SMR 23 in the battery pack B21 or B22 is maintained in a connected state (ON state). When both the battery packs B21 and B22 are charged at the same time, the SMR 23 of each of the battery packs B21 and B22 is controlled to be in the connected state.

[0032] The server 380 obtains information indicating the status (e.g., temperature, voltage, and SOC) of battery packs B21 and B22 from the BMSs 312a and 312b, respectively. The server 380 may charge the series-connected battery packs B21 and B22 with the power supply PS2 by turning relays R1A, R2A, and R3A OFF, ON, and OFF, respectively. The server 380 may charge the parallel-connected battery packs B21 and B22 with the power supplies PS1 and PS2 by turning relays R1A, R2A, and R3A ON, OFF, and ON, respectively. The server 380 may charge the battery pack B21 with the power supply PS1 by turning relays R1A, R2A, and R3A ON, OFF, and OFF, respectively. The server 380 may charge the battery pack B22 with the power supply PS2 by turning relays R1A, R2A, and R3A OFF, OFF, and ON, respectively. In this embodiment, the switching circuit 30 and the switching circuit 30A correspond to examples of the "first switching circuit" and the "second switching circuit" according to the present disclosure, respectively. The switching circuit 30 and the switching circuit 30A may have different configurations. The switching relay of the switching circuit 30A may have higher durability (e.g., durability against overcurrent) than the switching relay of the switching circuit 30.

[0033] The second storage device 320 stores a plurality of battery packs collected from a plurality of vehicles. The second storage device 320 may include an inspection device and a sorting device in addition to a pack storage section. For battery packs B11 and B12 removed from the vehicle body 10, a recycling process is carried out by the second storage device 320, a collection device 330, and a filling device 340, for example, as shown in FIG. 3. The exchange process by the battery exchange system 300 will be described in detail later.

[0034] When server 380 receives a replacement request from the user of the target vehicle, it starts a processing flow (see FIG. 5 described later) for replacing the power storage device of the target vehicle. The user of the target vehicle can send the replacement request to server 380 by operating a user terminal. In this embodiment, vehicle 100 corresponds to the target vehicle, and mobile terminal 600 functions as the user terminal.

[0035] The mobile terminal 600 is, for example, a smartphone. The smartphone has a built-in computer and is equipped with a touch panel display and a speaker. Application software for using the services provided by the server 380 is installed in the mobile terminal 600. However, the mobile terminal 600 is not limited to a smartphone, and may be a portable game console or an electronic key, a wearable device, or a terminal implanted in the user (human body).

[0036] When the application software is started, the mobile terminal 600 displays, for example, a screen Sc1 shown in Fig. 4. Fig. 4 is a diagram for explaining an exchange request.

[0037] 4, the screen Sc1 includes an information section M1 and operation sections M2 to M5. The information section M1 displays the SOC (SOC A ) and the SOC of the battery pack 20B (SOC B) in the vehicle body 10. The operation unit M2 indicates the positions of the battery packs 20A, 20B in the vehicle body 10 and accepts the designation of the battery pack to be replaced. The information unit M1 and the operation unit M2 display information about each battery pack, distinguishing them by the battery pack's identification information (1, 2). The operation unit M3 accepts the designation of a target SOC. The user can designate the target SOC by selecting a target SOC from predetermined options or by inputting a numerical value indicating the target SOC. The operation unit M4 accepts the designation of an exchange station. The user can designate an exchange station by selecting the exchange station closest to the current position of the vehicle 100 or by selecting another exchange station from among multiple exchange stations on the map. When the user operates the operation unit M5 (e.g., the enter button) after at least one battery pack has been selected by the operation unit M2, the target SOC has been designated by the operation unit M3, and an exchange station has been designated by the operation unit M4, the mobile terminal 600 sends a replacement request to the exchange station designated by the operation unit M4. In this embodiment, an exchange station including the battery exchange system 300 shown in Fig. 3 is designated by the user. For this purpose, an exchange request is sent from the mobile terminal 600 to the server 380. The exchange request may be sent from the mobile terminal 600 to the server 380 via another server. The mobile terminal 600 sends the exchange request together with information input by the user to the mobile terminal 600 (hereinafter referred to as "user exchange information") and identification information and specification information of the vehicle 100 (hereinafter referred to as "target vehicle information") to the server 380. The user exchange information indicates one or more battery packs selected by the operation unit M2 and a target SOC designated by the operation unit M3.

[0038] The mobile terminal 600 sends the exchange request to the server 380 before the target vehicle (vehicle 100) arrives at the exchange station. Upon receiving this exchange request, the server 380 starts the processing flow of S31 to S37 shown in Fig. 5. Fig. 5 is a flowchart showing the processing related to the battery exchange method. "S" in the flowchart means a step.

[0039] 3 and 5, in S31, the server 380 selects the requested number of battery packs that meet the specifications of the vehicle 100 from the battery packs (inventory) held by the first storage device 310 based on the user replacement information and the target vehicle information. The number of battery packs selected here corresponds to the number of battery packs (number of replacements) indicated by the user replacement information. When selecting multiple battery packs, the server 380 may select them using at least one of the capacity, degree of deterioration, and voltage of each battery pack included in the candidates (inventory). The server 380 may preferentially select multiple battery packs that have similar capacities, degrees of deterioration, or voltages.

[0040] In the following S32, the server 380 determines whether multiple battery packs were selected in S31. For example, if the replacement request requests replacement of battery packs 20A and 20B in the vehicle 100, a YES determination is made in S32, and the process proceeds to S33. The following describes the case where battery packs B21 and B22 are selected in S31. The selected battery packs B21 and B22 are set in the charging device 312 by, for example, the supply device 311.

[0041] In S33, the server 380 controls the charging device 312 so that the voltage difference between the battery packs B21 and B22 is reduced. Specifically, the charging device 312, in accordance with instructions from the server 380, charges the battery packs B21 and B22 individually so that the voltage difference between the battery packs B21 and B22 measured by the BMSs 312a and 312b is equal to or less than a predetermined reference value. The SMRs 23 in the battery packs to be charged are controlled to be connected. The battery packs B21 and B22 are charged in a disconnected state. The voltage of each of the battery packs B21 and B22 tends to increase as the amount of stored power increases.

[0042] In the following S34, the server 380 controls the charging device 312 so that the battery packs B21 and B22 are connected in parallel. Specifically, the server 380 connects the SMRs 23 of each of the battery packs B21 and B22 to the connected state and turns the relays R1A, R2A, and R3A of the switching circuit 30A ON, OFF, and ON, respectively, thereby connecting the battery 21 in the battery pack B21 and the battery 21 in the battery pack B22 in parallel. This allows voltage adjustment through the exchange of power between the battery packs, further reducing the voltage difference between the battery packs. Because individual charging (S33) has been performed in advance, overcurrent during parallel connection is suppressed.

[0043] In the following S35, the server 380 controls the charging device 312 so that the parallel-connected battery packs B21 and B22 are charged. Specifically, the charging device 312, in accordance with the instruction from the server 380, charges the parallel-connected battery packs B21 and B22 until the SOC of at least one of the battery packs B21 and B22 reaches the target SOC indicated by the user exchange information. When the SOC of one of the battery packs B21 and B22 reaches the target SOC, the server 380 instructs the charging device 312 to end charging, even if the SOC of the other battery pack has not yet reached the target SOC. Charging the battery packs B21 and B22 in parallel can prevent the voltage difference between the battery packs B21 and B22 from increasing during charging.

[0044] If the replacement request requests replacement of only one of battery packs 20A, 20B in vehicle 100, a NO determination is made in S32, and the process skips S33 and S34 and proceeds to S35. In this case, the battery pack selected in S31 is set in charging device 312. Then, in S35, the set battery pack is charged alone. As a result of this charging, the SOC of the battery pack selected in S31 becomes the target SOC.

[0045] Next, in S36, the server 380 determines whether the target vehicle (vehicle 100) has arrived at the exchange station. In S36, the server 380 waits for the arrival of the target vehicle.

[0046] When the vehicle 100 is parked in a predetermined position within the exchange station, the ECU 500 starts the process flow of S11 to S16. In S11, the ECU 500 sends an arrival notification to the server 380 together with the identification information (vehicle ID) of the vehicle 100. In the following S12, the ECU 500 determines whether or not the battery pack has been exchanged. The determination in S12 is repeatedly executed while the battery pack exchange is not complete (NO in S12).

[0047] When the vehicle ID in the received arrival notification matches the vehicle ID in the exchange request (target vehicle information), the server 380 determines that the target vehicle has arrived at the exchange station. When charging by the charging device 312 (S35) is completed and the target vehicle has arrived at the exchange station (YES in S36), the server 380 replaces, in S37, the battery pack specified by the user exchange information among the multiple battery packs installed in the target vehicle with the battery pack selected in S31. For example, when battery packs 20A and 20B in the vehicle 100 are specified by the user exchange information, battery packs 20A and 20B (battery packs B11 and B12) are replaced as shown in FIG. 3. Specifically, the server 380 controls the exchange device 350 to remove battery packs B11 and B12 from the vehicle body 10. This separates the vehicle body 10 from the battery packs B11 and B12. Next, the server 380 controls the supply device 311 so that the battery packs B21 and B22 charged in S33 to S35 are transported (supplied) from the first storage device 310 to the exchange device 350. Next, the server 380 controls the exchange device 350 so that the battery packs B21 and B22 are attached to the vehicle body 10. At this time, the SMR 23 of each of the battery packs B21 and B22 is in the open state. Then, the server 380 transmits a signal notifying the completion of the battery pack attachment (hereinafter referred to as the "exchange completion signal") to the ECU 500. Note that if only one of the battery packs 20A and 20B in the vehicle 100 is specified by the user replacement information, the server 380 transmits the exchange completion signal after the one battery pack selected in S31 is attached to the vehicle body 10 in place of the battery pack 20A or 20B. After transmitting the exchange completion signal, the server 380 may charge the user of the vehicle 100 a fee according to the target SOC.

[0048] FIG. 3 shows an example in which the removal and installation of a battery pack are performed in different positions. The vehicle position may be adjusted before the removal of the battery pack, before the installation of the battery pack, or both. A transport device (e.g., a conveyor-type transport device) or a transport robot (not shown) may move the vehicle. However, the removal and installation of the battery pack may also be performed in the same position. The battery pack replacement (removal and installation) may be performed while the vehicle is stationary. The transport method for each of the supply device 311, the collection device 330, and the filling device 340 is also arbitrary. These transport methods may be a conveyor type or a method using a transport robot. A user may manually replace the battery pack (power storage device) instead of using the replacement device 350.

[0049] At least one battery pack (hereinafter referred to as a "replacement pack") attached to the vehicle body 10 by the processing of S37 has the same configuration as battery pack 20A or 20B (FIGS. 1 and 2). By the processing of S37, the low-voltage power supply line and communication line of the replacement pack are connected to the low-voltage power supply line and communication line of the vehicle body 10, respectively. However, the high-voltage power supply line is cut off by the SMR 23 of the replacement pack. After the processing of S37, the processing flow of S21 to S24 is executed for each replacement pack.

[0050] In S21, the ECU 28 of the replacement pack is activated by power supplied from the power source (auxiliary battery 17) within the vehicle body 10. Subsequently, in S22, the activated ECU 28 transmits information indicating the state of the replacement pack (hereinafter referred to as "state information") to the ECU 500. The state information indicates, for example, the current state of the battery 21 (e.g., voltage and temperature) detected by the BMS 22. Subsequently, in S23, the ECU 28 determines whether or not an SMR-on command has been received from the vehicle body 10. The ECU 28 waits for an SMR-on command from the vehicle body 10 in S23 while maintaining the SMR 23 in the open state.

[0051] Meanwhile, after processing S37, the ECU 500 receives a replacement completion signal from the server 380. As a result, a YES determination is made in S12, and the process proceeds to S13. In S13, the ECU 500 determines whether or not the above-mentioned status information has been received from the replacement pack. If the ECU 500 receives the status information (YES in S13), the ECU 500 determines whether or not the replacement pack is normal based on the status information in S14. If the replacement pack is normal (YES in S14), the ECU 500 sets the SMR 13 to a connected state (ON state) and the switching relays of the switching circuit 30 to a parallel connection state (relay R1: ON, relay R2: OFF, relay R3: ON) in S15, and transmits an SMR ON command to the replacement pack. Thereafter, the process flow ends. On the other hand, if an abnormality has occurred in the replacement pack (NO in S14), the ECU 500 performs a predetermined notification process in S16, and then the process flow ends. In S16, the ECU 500 may cause the HMI 19a to execute a notification process. The HMI 19a may notify the user that an abnormality has occurred by, for example, at least one of a display, a sound (including voice), and a lamp lighting (including blinking).

[0052] When the ECU 28 of the replacement pack receives an SMR-on command (S15) from the vehicle body 10 (YES in S23), it switches the SMR 23 from the open state (disconnected state) to the closed state (connected state) in S24. This ends the processing flow. The replacement pack goes through the above-described processing flow to operate as battery pack 20A or 20B (FIGS. 1 and 2). The processing in S24 puts the batteries 21a and 21b mounted on the vehicle 100 in a parallel state. Thereafter, when the vehicle 100 starts traveling, the ECU 500 may put the battery packs 20A and 20B (and thus the batteries 21a and 21b) in a series state.

[0053] In the power storage device exchange system according to this embodiment, when the exchange device 350 exchanges the battery pack B11 (first power storage device) and the battery pack B12 (second power storage device) mounted on a target vehicle with the battery pack B21 (third power storage device) and the battery pack B22 (fourth power storage device), prior to the exchange, the charging device 312 charges at least one of the battery packs B21 and B22 so as to reduce the voltage difference between the battery packs B21 and B22 (S33). Therefore, an overcurrent is unlikely to occur when the battery packs 20A and 20B (and thus the batteries 21a and 21b) are connected in parallel.

[0054] The functions of server 380 described above may be realized by hardware (e.g., electronic circuits) alone, or may be realized by using software. The functions of server 380 may be divided into multiple units. For example, the function of controlling charging device 312 and the function of communicating with the user terminal of the target vehicle and managing information may be implemented in separate units.

[0055] 3 is an on-premise server. However, the management device may be at least one computer on the cloud. For example, the functions of the server 380 may be implemented on the cloud. Instead of the mobile terminal 600, an HMI 19a (vehicle-mounted HMI) may be employed as the user terminal.

[0056] The processing flow shown in Fig. 5 can be modified as appropriate. For example, the order of processing can be changed or unnecessary steps can be omitted depending on the purpose. Furthermore, the content of any of the processing can be changed. For example, either S33 or S34 can be omitted.

[0057] The configuration of the vehicle is not limited to the configuration described above (see FIG. 2). For example, either one of SMRs 13 and 23 may be omitted. Furthermore, all of SMRs 13, 23a, and 23b may be omitted. The vehicle may include three or more power storage devices (for example, detachable battery packs). The vehicle is not limited to a passenger car, but may also be a bus or truck. The vehicle may be configured to be capable of contactless charging. The vehicle may also include solar panels. The vehicle may be configured to be capable of autonomous driving, or to be capable of unmanned travel.

[0058] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0059] 10 vehicle bodies, 20A and 20B battery packs, 21a and 21b batteries, 30 and 30A switching circuits, 100 vehicles, 380 servers, 500 ECUs, and 600 mobile terminals.

Claims

1. A system for replacing an electricity storage device, The system includes a charging device and an exchange device; the replacement device is configured to replace the power storage device of the target vehicle; The target vehicle is A plurality of power storage devices; a first switching circuit configured to be able to switch between a series state in which the plurality of power storage devices are connected in series and a parallel state in which the plurality of power storage devices are connected in parallel; Equipped with A storage device exchange system in which, when the exchange device exchanges a first storage device and a second storage device mounted on the target vehicle with a third storage device and a fourth storage device, prior to the exchange, the charging device charges at least one of the third storage device and the fourth storage device so as to reduce a voltage difference between the third storage device and the fourth storage device.

2. the charging device includes a second switching circuit configured to be able to switch between a series state in which the third power storage device and the fourth power storage device are connected in series and a parallel state in which the third power storage device and the fourth power storage device are connected in parallel, the charging device charges the third power storage device and the fourth power storage device by connecting the third power storage device and the fourth power storage device in a parallel state; 2. The power storage device exchange system according to claim 1, wherein the exchange device exchanges the first power storage device and the second power storage device in the target vehicle with the third power storage device and the fourth power storage device after charging by the charging device is completed.

3. 3. The energy storage device exchange system according to claim 2, wherein when the first energy storage device and the second energy storage device are exchanged for the third energy storage device and the fourth energy storage device by the exchange device, the target vehicle places the third energy storage device and the fourth energy storage device in a parallel state.

4. The system further comprises a management device; The charging device and the exchange device are installed in a predetermined area, the management device is configured to receive a replacement request from a user of the target vehicle before the target vehicle arrives in the predetermined area; 2. The energy storage device exchange system of claim 1, wherein after receiving the exchange request requesting exchange of the first energy storage device and the second energy storage device in the target vehicle, the management device instructs the charging device to charge the third energy storage device and the fourth energy storage device to reduce a voltage difference between the third energy storage device and the fourth energy storage device.

5. the replacement request indicates a target SOC; 5. The energy storage device exchange system of claim 4, wherein when a voltage difference between the third energy storage device and the fourth energy storage device becomes equal to or less than a reference value and an SOC of at least one of the third energy storage device and the fourth energy storage device reaches the target SOC, the management device instructs the charging device to end charging.

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